Field of the Invention
The invention relates to a device for discharging a liquid lubricant, in particular bearing oil, from a bearing configuration for a shaft which rotates around an axis. The bearing configuration has a bearing, upon which the liquid lubricant acts and which mounts the shaft, at least one seal, which is adjacent to the bearing and encircles the shaft, and a collecting chamber for intercepting and channeling away escaping lubricant. The invention also relates to a process for discharging a liquid lubricant from the bearing configuration, in particular for a shaft of a steam turbine.
The invention is concerned, in particular, with sliding-bearing configurations in a turbine installation, in particular in a steam-turbine installation. Sliding-bearing configurations which can be used in turbine installations and a process and a device for discharging liquid lubricant, in particular lubricating oil, from such sliding-bearing configurations can be gathered, for example, from Published European Patent Application EP 0 306 634 A2, corresponding to U.S. Pat. No. 4,741,630, and from Published International Patent Application WO 94/01713 A1, corresponding to U.S. Pat. No. 5,494,355.
A contactless shaft seal with a leakage-oil discharge that ensures a rapid discharge of the bearing oil flowing off from the sliding-bearing surfaces in the case of a sliding bearing for turbomachines, in particular steam turbines, in a wide speed range, starting from rest and going beyond the turnover speed up to the operational speed (e.g. 3000 rpm) is described in the Published European Patent Application EP 0 306 634 A2. Provided for this purpose is a device with an oil-collecting annular duct that is made in an arcuate section in the form of a slot-like opening curve. This results in the opening curve passing over a circumferential angle region of the shaft which begins at the geodetically lowest point of the annular-duct outer contour and extends, as seen in the direction of rotation of the shaft, at most up to the bearing-shell joint of the oil-collecting annular duct. For a discharge of leakage oil which has penetrated into the seal of the sliding bearing, a leakage-oil collecting chamber is welded on geodetically beneath the seal. The leakage-oil collecting chamber opens out, via axially oriented suction-removal bores, into suction-producing drive nozzles which are located, in the form of suction caps, in the oil outflow of the oil-collecting annular duct. This is also intended to discharge the leakage oil to a certain extent from the seals assigned to the sliding bearings.
A process and a device for discharging lubricant, in particular bearing oil, from a bearing configuration, in particular an end journal bearing of a steam turbine is specified in the Published International Patent Application WO 94/01713 A1. In this case, the end journal bearing is assigned a seal that encircles the turbine shaft. Provided therebetween is a collecting chamber that encircles the shaft and into which the lubricant that escapes from the bearing along the shaft flows and from which the lubricant is discharged. The lubricant is discharged from the collecting chamber without any great loss in speed. The bearing oil is fed to a flow-off line by way of an injection line. The configuration has an injection line and a flow-off line forming a suction-action-producing jet pump.